Structure of a greenhouse

ABSTRACT

A greenhouse has an exterior curtain wall structure formed by spaced tubular posts carrying external transparent panels and bottom non-transparent wall panels below a sill with the panels spanning the posts. A plurality of elongate benches is located within the interior at spaced positions along one side wall with the width of the benches being equal to the post spacing to form a modular construction. Each bench has associated with it a respective air handling system for conditioning including a duct which is located partly under the respective bench and a fan in a fan housing at the side wall. From the fan a vertical duct section extends to a flexible tube extending over the bench. An alley is arranged along the opposite wall containing electrical controls mounted in cabinets forming panels for mounting in the span between posts. Air dehumidification, fogging, heating and cooling are provided in the duct under the bench.

This application is a continuation-in-part application of applicationSer. No. 10/616,296, filed Jul. 10, 2003 and now issued as U.S. Pat. NoINSERT.

This invention relates to a structure of a greenhouse.

The term greenhouse as used herein is intended to be primarily but notexclusively directed to environmentally controlled growth chambers usingprimarily natural light and thus having transparent walls, andparticularly to such structures having uniform and accurate control ofthe interior environment. Such structures are primarily intended for usein research or other similar environments where uniform and accuratecontrol is of high importance rather than in crop production facilitieswhere such close control of the environment cannot be economicallyjustified. However the present invention is not intended to be limitedto any particular type or use of such a facility.

This application is related to a series of two further applications allfiled simultaneously with this application and assigned to the sameassignee as follows:

application Ser. No. 10/616,297 filed Jul. 10, 2003 and entitledLighting system for a Greenhouse;

application Ser. No. 10/616,298 filed Jul. 10, 2003 and entitled ClimateControl for a Greenhouse.

The disclosures of the above applications are incorporated herein byreference.

BACKGROUND OF THE INVENTION

Greenhouses used for research and high value production often includecomplex and expensive climate control systems for controlling airquality including temperature control by heating and cooling asrequired, and humidity, by de-humidification and humidification asrequired. Also such greenhouses are generally designed so as to maximizelight availability to the growing plants. Such greenhouses therefore mayinclude shades and lighting systems so as to control the lightavailability.

Up until now such greenhouses have generally been manufactured in thesame manner as commercial buildings in that different contractors andsuppliers are contracted to assembly the exterior structure, to provideair handling equipment, to provide electrical control systems, toprovide shading systems and to provide lighting systems.

Thus the exterior structure is initially constructed using availableconstructions systems to provide a primarily transparent exteriorstructure. However the benches for supporting the plants, the airhandling system and the remaining components are not necessarilymanufactured so as to best fit within the exterior structure. Thusadditional design effort is necessary to design and construct each ofthe separate components to match the structure of the exterior.

The arrangement disclosed hereinafter is designed based upon the conceptthat the greenhouse be supplied as a complete structure in which thenecessary components are arranged and designed each in relation to theothers so as to provide an assembly which is expandable in nature and inwhich each component is best suited to match the structure andarrangement of the remaining components.

SUMMARY OF THE INVENTION

It is one object of the present invention, therefore, to provide animproved greenhouse structure.

According to a first aspect of the invention there is provided agreenhouse comprising:

an exterior wall structure which includes primarily transparent panelsallowing entry to an interior of natural light;

a plurality of elongate benches located within the interior and arrangedto provide support surfaces for supporting crop materials thereon forreceiving the natural light and growing within the interior;

an air handling system for conditioning the air within the interiorincluding at least one air moving fan, at least one interior air intake,at least one interior air outlet, at least one exterior vent and atleast one component for changing air temperature;

the exterior wall structure including a first side and a second sidewall opposite to the first side wall with each of the first and secondside walls defined by a plurality of vertical posts at spaced positionsalong the length of the side wall defining equal spans between each ofthe plurality of vertical posts and the next with transparent panelsarranged to substantially fill the span between the posts;

each bench having a bench support for the bench located underneath thebench;

the benches being arranged at spaced positions along the first side wallsuch that each bench has one end adjacent said first side wall such thatthe bench and the bench support therefor each extend from the first sidewall at right angles thereto toward the second side wall;

each bench being associated with a respective one of the spans such thatthe number of spans is equal to the number of benches and such that thebench support of each bench is located between the posts of theassociated respective one of the spans.

Preferably the width of each bench of the plurality of benches issubstantially equal to the width of the spans.

Preferably the side walls at right angles to said one side wall eachhave the same spans between the posts thereof and the length of eachbench from said one side wall is equal to a multiple of the spans.

Preferably each of the benches is located such that it has one end atsaid one side wall and has an opposed end spaced from said oppositewall.

Preferably the span equals six feet.

Preferably the posts and panels form a curtain wall construction inwhich the panels are attached at their edges to the posts and fullyextend across the span therebetween without intermediate supportelements.

According to a second aspect of the invention there is provided agreenhouse comprising:

an exterior wall structure which includes primarily transparent panelsallowing entry to an interior of natural light;

a plurality of elongate benches located within the interior and arrangedto provide support surfaces for supporting crop materials thereon forreceiving the natural light and growing within the interior;

an air handling system for conditioning the air within the interiorincluding at least one air moving fan, at least one interior air intake,at least one interior air outlet, at least one exterior vent and atleast one component for changing air temperature;

the exterior wall structure including a first side and a second sidewall opposite to the first side wall with each of the first and secondside walls defined by a plurality of vertical posts at spaced positionsalong the length of the side wall defining equal spans between each ofthe plurality of vertical posts and the next with transparent panelsarranged to substantially fill the span between the posts;

the benches being arranged at spaced positions along the first side wallsuch that each bench has one end adjacent said first side wall andextends therefrom at right angles thereto toward the second side wall;

each bench being associated with a respective one of the spans betweenthe posts of said first side wall and arranged such that the number ofspans is equal to the number of benches;

wherein the width of each bench is substantially equal to the width ofthe spans;

and wherein at least some of the benches are mounted for side to sidesliding movement and at least one of the benches has a width which isnarrower than that of the spans so as to allow a space between thebenches for user access.

Preferably the side walls at right angles to said one side wall eachhave the same spans between the posts thereof and the length of eachbench from said one side wall is equal to a multiple of the spans.

Preferably each of the benches is located such that it has one end atsaid one side wall and has an opposed end spaced from said oppositewall.

Preferably the span equals six feet.

Preferably the posts and panels form a curtain wall construction inwhich the panels are attached at their edges to the posts and fullyextend across the span therebetween without intermediate supportelements.

According to a third aspect of the invention there is provided agreenhouse comprising:

an exterior wall structure which includes primarily transparent panelsallowing entry to an interior of natural light;

a bench arranged to be located within the interior and provide supportsurfaces for supporting crop materials thereon for receiving the naturallight and growing within the interior; and

and an air handling system comprising:

an air intake plenum having at least one air intake,

a fan connected to the plenum,

an outlet duct connected to the fan having an air outlet for expellingair from the duct into the interior of the greenhouse,

and at least one air conditioning component for conditioning the airtransported from the plenum to the duct by the fan;

wherein the plenum includes at least two inlets and wherein there isprovided at each of the inlets within the duct a cooling coil forcooling the air;

and wherein the supply of cooling fluid to each of the coils iscontrolled by a cooling system which is arranged to effect sub-coolingat one of the coils for de-humidifying the air.

According to a fourth aspect of the invention there is provided agreenhouse comprising:

an exterior wall structure which includes primarily transparent panelsallowing entry to an interior of natural light;

a bench arranged to be located within the interior and provide supportsurfaces for supporting crop materials thereon for receiving the naturallight and growing within the interior; and

and an air handling system comprising:

an air intake plenum having at least one air intake,

a fan connected to the plenum,

an outlet duct connected to the fan having an air outlet for expellingair from the duct into the interior of the greenhouse,

and at least one air conditioning component for conditioning the airtransported from the plenum to the duct by the fan;

wherein the plenum contains fogging nozzles for applying water dropletsto the air;

and wherein the fogging nozzles are supplied with water under pressurefrom a fogging water supply system including a water pump operable tosupply water under pressure to an accumulator tank having a gasmembrane, the tank being arranged to supply the water under pressure tothe nozzles and including a pressure control valve arranged to operatethe pump to maintain the pressure within the tank between upper andlower pressure limits so as operate the pump only when the lowerpressure limit is reached.

According to a fifth aspect of the invention there is provided agreenhouse comprising:

an exterior wall structure which includes primarily transparent panelsallowing entry to an interior of natural light;

a bench arranged to be located within the interior and provide supportsurfaces for supporting crop materials thereon for receiving the naturallight and growing within the interior; and

and an air handling system comprising:

an air intake plenum having at least one air intake,

a fan connected to the plenum,

an outlet duct connected to the fan having an air outlet for expellingair from the duct into the interior of the greenhouse,

and at least one air conditioning component for conditioning the airtransported from the plenum to the duct by the fan;

wherein the fan is mounted in a fan housing with the fan housing at oneend of the bench arranged to be located at one exterior wall of thegreenhouse and wherein the fan housing has a connection for exterior airarranged to extend through said one exterior wall.

According to a sixth aspect of the invention there is provided agreenhouse comprising:

an exterior wall structure which includes primarily transparent panelsallowing entry to an interior of natural light;

a bench arranged to be located within the interior and provide supportsurfaces for supporting crop materials thereon for receiving the naturallight and growing within the interior; and

and an air handling system comprising:

an air intake plenum having at least a part thereof located underneaththe bench;

at least one air outlet for expelling air into the interior of thegreenhouse;

a fan connected to the plenum for driving air in the plenum from theinlet to the outlet;

and at least one air conditioning component in the part of the plenumunderneath the bench for conditioning the air;

wherein the fan is mounted in a fan housing with the fan housing at oneend of the bench arranged to be located at one exterior wall of thegreenhouse and wherein the air inlet is arranged to extend through saidone exterior wall.

Preferably the air conditioning component comprises an air coolingdevice.

Preferably the air conditioning component comprises a plurality of aircooling devices located at spaced positions within the part of theplenum underneath the bench.

Preferably the at least one air outlet comprises a plurality of outletsat spaced positions on the part of the plenum under the bench.

Preferably the at least one air conditioning component comprises aplurality of evaporative air cooling devices each located at arespective one of the outlets.

BRIEF DESCRIPTION OF THE DRAWINGS

One embodiment of the invention will now be described in conjunctionwith the accompanying drawings in which:

FIG. 1 is a plan view of a greenhouse according to the presentinvention.

FIG. 2 is a longitudinal cross sectional view through one of the benchesof FIG. 1 showing the air handling and conditioning components therein.

FIG. 3 is a transverse cross sectional view of the one of the benches ofFIG. 1 showing the bench sliding and tilting features.

FIG. 3A is a transverse cross sectional view of the a plurality of thebenches of FIG. 1 showing the position of the benches relative to oneanother and to the end wall.

FIG. 4 is a cross sectional view through the fan housing and curtainwall at the end of one of the benches of FIG. 1 showing the location ofthe fan housing relative to the wall, the inlet and outlet openings tothe fan housing from the exterior and the location of the channel orchase within the knee wall construction.

FIG. 5 is a transverse cross sectional view through whole structure ofFIG. 1 showing arrangement of the posts and trusses and showing the roofventing openings for co-operation with the air handling systems.

FIG. 6 is a cross sectional view through the junction between a post androof truss showing the steel interconnections within the interior of thetubular frame members.

FIG. 7 is a horizontal cross sectional view through a post and itssupported panels showing the curtain wall construction.

FIG. 8 is a plan view on an enlarged scale of the alley showing the planview of the control cabinets forming the wall panels in the alley.

FIG. 9 is an elevational view of the components shown in FIG. 8 of thealley showing the elevational view of the control cabinets and doorpanel forming the panels in the alley.

FIG. 10 is a schematic layout of the pressurized water supply system forthe fogging nozzles in the air handling duct of FIG. 1 showing thearrangement of pump and accumulator.

FIG. 11 is a longitudinal cross sectional view through one of thebenches of FIG. 1 showing an alternative arrangement for the airhandling and conditioning components therein

DETAILED DESCRIPTION

A greenhouse structure is shown in FIG. 1 and comprises an exterior wall10 supported on a suitable concrete foundation 11 and defining sidewalls 12 and 13 of the greenhouse together with a first end wall 14 anda second end wall 15. Parallel to the end wall 15 is provided an alleywall 16 so that between the parallel walls 15 and 16 is an alleyway 17.A first door 18 allows access into the alley and is provided in wall 16and a second door 19 is mounted in the wall 15 so as to allow accessfrom the alley into the main interior of the greenhouse.

Within the greenhouse is mounted a plurality of greenhouse benchesgenerally indicated at 20, each of which comprises an air handlingsystem and a bench top support for plants. The greenhouse ismanufactured as an expandable system so that the number of benches to becontained within the greenhouse can be increased or decreased inaccordance with requirements by selecting a desired length of thegreenhouse to accommodate an according respective number of benches.Thus the outside wall structure is formed in sections which can be addedand are associated in width with the benches and associated air handlingsystem so that an addition of further wall sections can be complementedby the same number of additional benches.

Thus the wall 14 is formed from posts 21 and corner posts 22. Thedistance between each of the post is arranged to be equal to the nominalwidth of a bench so that each bench fits between a post on the nextadjacent post and extends from the wall 14 at right angles to that wallin a direction toward the opposite wall 15. It will be appreciatedtherefore that the addition of further posts thus increasing the lengthof the wall 14 and of course the corresponding length of the wall 15allows the addition of further benches of the same width and samestructure as those shown in FIG. 1.

Also shown in FIG. 1 is a lighting system comprising four rows 23 oflamps. Each of the rows 23 is aligned with a respective one of the postsso that two of the rows are directly aligned with the posts 21. Ofcourse the rows at the walls 12 and 13 are necessarily moved slightlyinwardly from the wall so as to be approximately aligned with the post22 but move slightly inwardly to be located within the wall structurewhich is aligned with the respective corner post described in moredetail hereinafter.

Turning now to FIGS. 4, 5, 6, and 7, the structure of the greenhouse isshown in more detail. Thus from FIG. 5 it will be noted that thegreenhouse includes a roof generally indicated at 24 which includestrusses 27 defined by roof rafters 25 converging to an upper apex 26 andhorizontal bottom beams 28 interconnected by suitable reinforcingmembers 27A. The height of the walls is generally of the order of 14feet thus defining a generally shallow roof structure as is well knownin greenhouse construction. The alleyway 17 between the end wall 15 andthe alley wall 16 is formed as an extra structure on the otherwisesymmetrical greenhouse construction with the roof line defined by therafters 25A extending downwardly over the alleyway to terminate at thetop of the post forming the wall 16.

The walls and roof are formed as a curtain wall structure defined byextruded tubular posts 30 (as shown in FIG. 7) and cladding panels 31.The posts 30 are connected one to the next by steel structural members32 which have legs arranged to insert into the hollow interior of thetubular members 30 so as to provide a connection of each tubular memberto the next and reinforcement of the tubular members at the connections.Thus in FIG. 6 is shown a connection at the top of the post 15 definedby the tubular member 30 which is connected to the roof rafter 25Aformed by a further tubular member 30 by the inserted steelreinforcement 32 which has legs 33, 34 and 35 which extend into sectionsof the tubular members 30 at the junction.

At the bottom of each post of the side walls is formed a mountingbracket 36 which attaches the bottom of the post 15A to the concretefloor as shown in plan in FIG. 7.

The cladding panels 31 are attached to the tubular members 30 by a cap37. Thus the tubular member 30 defines a main tubular portion ofrectangular construction having a front wall 38 and side walls 39 and40. The side walls 39 and 40 extend beyond the front wall 38 into areceptacle section 40 which defines two butting ends 39A and 40A betweenwhich is provided a web section 38A extending outwardly from at rightangles to the end wall 38. The end of the web section 38A is formed intoa channel 38B which faces outwardly from the tubular member and isprojecting between the butting ends 39A and 40A. The cap 37 is formed intwo parts including an inner part 37A and an outer end 37B. These twoparts clip together. The inner part 37A forms a pair of faces facingtoward the end faces 39A and 40A so as to define a channel therebetweenfor receiving two panels 31 and 31A. Thus the panels are held in placeagainst the tubular member by the end cap. This structure thereforeforms a curtain wall in that the system comprises the posts which arespaced by the span of the panels and the panels are held against theposts to cooperate with the posts in forming the structural stability.The inner part of the end cap 37 is held in place against the web 38A bya screw fastener which engages into the channel portion 38B thus holdingthe cap held fixed against a tubular member.

Curtain wall structures of this type are known and other profiles of thetubular members and associated caps can be provided and are availablefrom other manufacturers.

As shown in FIG. 1, the posts along each of the side walls are formed bythe tubular members 30 and the panels 31. At the corners, it will beappreciated that it is necessary to provide an additional tubular memberattached to the main tubular member which provides a receptacle for twofurther panels. Again various arrangements are available for providing acurtain wall structure of this type.

As shown in FIG. 4, the panels 31 are separated by horizontal mullions41 which extend across between the tubular members 30. Thus the panels31 are rectangular and span between the posts and are formed of arequired height so that a specified number of the panels forms a heightof the wall up to the roof structure. The panels are thus separated bythe transverse mullion which provide a similar channel and caparrangement by which the panels are attached to the mullion.

The panels 31 are transparent to allow the passage of exterior lightinto the greenhouse for providing energy to the plants in a conventionalmanner. A sill 42 is provided at the height of the benches so that belowthe height of the benches the walls are formed from insulated opaquepanels 43. The sill 42 is attached to the tubular member and extendsoutwardly to an outermost edge 42A which is spaced outside the wall 38of the tubular member. The sill thus acts to shed water in aconventional manner from the glass panels so that the water is shed awayfrom the base of the post. The insulated panels 43 extend from the sillto a bottom connector 44 which sits on the concrete base 11. The panels43 in all of the walls except the end wall 14 are simply solid panelswith insulation formed as part of the panel thus defining an outersurface 45 at the outer edge 42A of the sill and inner surface 46 whichis located underneath the sill and thus spaced outwardly from thetubular member and spaced outwardly from the end wall 38 thereof, withthe web 38A removed in this section. This defines therefore an openchannel between the inside surface 46 and the tubular members formingthe posts thus forming a channel or chase for the passage of electricalleads, control leads and piping for heating and cooling fluids.

In the end wall 14 as shown in FIG. 4, the panel 43 is perforated toform louvers 47 for communication with the fan housing describedhereinafter.

Turning now to FIGS. 1, 2, 3 and 3A, the construction of each of thebenches including the associated air handling system of the climatecontrol system. Each of the benches 20 comprises a plenum 50 a fanhousing 51, an outlet duct 52 from the fan housing which includes avertical duct portion 53 and a horizontal duct portion 54. On top of theplenum 50 is mounted a bench tray 55 which extends from a first end 56at the fan housing 51 to a second end 57 projecting beyond an end 58 ofthe plenum 50. The plenum 50 also has a second end 59 which provides anintake to the fan housing 51 and particularly to a fan 60 mounted withinthe fan housing.

It will be noted from FIGS. 1 and 3A that the fan housing 51 forms arectangular structure with a base sitting on the concrete floor 11 anupper surface 61 to which the duct portion 53 is attached. The fanhousing has sides 62 and 63 which are dimensioned so as to just fitbetween two of the posts of the end wall 14. Thus an end most one of thebenches 20 is located between the corner post 22 and the next adjacentpost 21 and a next one of the benches is located between the post 21 andthe next adjacent post 21. Thus the width of the benches is equal tosubstantially the span of the panels 31. The fan housing thus fitsbetween two of the posts and is pushed to a position as far outwardbetween the posts as is possible as best shown in FIG. 1 where the fanhousing projects to a position just beneath the height of the sill 42and located between the posts and extending substantially to the rear oroutside surface of the post but leaving the chamber underneath the sillaccessible for the communication of piping or wiring as previouslydescribed.

The bench trays 55 have an upper surface which is generally at the sameheight as the top surface 61 of the fan housing and the sill 42 of theframing structure. More particularly, the top surface of the fan housingis underneath the lowers mullion bar at a height of the order of 36inches. The bench trays are nominally at a height of the order of 32inches on top of which is received the plants and their containers. Thistherefore locates the growing plants on the bench tray at the sameheight as the bottom of the transparent panels 31. Each of the benchtrays includes side walls 64 which stand upwardly from a base 65 forminga rectangular container for the plants of a conventional nature. Withinthe tray is provided a support surface 66 which is formed of a sheetplastics material with ribs and channels for conducting water in aconventional manner well known to one skilled in the art.

Each of the rectangular trays has a length from the end 56 at the fanhousing to the end 57 projecting beyond the end wall 58 of the plenum50. Each of the trays has a width which is nominally equal to the widthbetween the posts 21 so that the side walls 67 of the tray abut the sidewalls 67 of the next adjacent tray to provide a generally orsubstantially continuous support surface for the growing plants. Thetrays of intermediate benches that is benches which are not at the sidewalls are equal in width to the spacing between the post 21. The endtrays have an end wall 67A which is spaced inwardly from the adjacentside wall 12 or 13 to leave an open space into which a user can walkalong the open area between the side wall 13 and the side of the plenum50 as indicated at 50A.

Each of the bench trays is mounted for sliding movement on bearingtracks 68 in a transverse side to side direction relative to the plenum50. It will be appreciated therefore that the space which is defined forthe user to enter into the position alongside the bench can be moved tothe other side of the bench by sliding the bench tray horizontallytoward the side wall 13. That space can then be moved to the other sideof the intermediate bench by sliding the bench tray of the intermediatebench again toward the side wall 14. Thus in an extended greenhousehaving many of the benches side by side, all of the benches except oneend one or except two end ones of the benches can extend the full widthbetween the posts and the user can get to the side of any one of thebenches simply by sliding the benches to the required position to movethe space to the required position allowing the user to walk between twoof the benches to access the bench on each side of the space. The amountof space necessary is generally of the order of twenty inches thusrequiring a sliding movement of each bench of the order of twenty inchesand requiring two, generally the endmost ones, of the benches to have areduced width of ten inches.

The spacing between the posts is equal to the width of the bench andparticularly the width of the bench trays as it is selected to be adistance of the order of six feet (or the metric equivalent of twometers) since this provides a bench tray which can be reached fromeither side with the user being able to reach across the centre line ofthe tray from one side and across the centre line of the tray from theother side allowing access to the full area defined by the tray. Thiswidth of six feet (two metres) is matched to the spacing between theposts so as to provide a modular structure in which the greenhouse canbe manufactured to accommodate different number of benches simply byadding an additional bay defined by one post and a series of panels andby adding another of the benches which is located between the posts inthat bay. The structure further allows the fan housing to be directlyassociated with the space between the two posts so that it canco-operate with the side wall of the panel below the sill as previouslydescribed. Each bench tray is associated with its own air handlingsystem of the climate control system so that air is properly distributedto the plants on the bench so that again the system is modular in thatadding a further bay provides the addition of one further bench and onefurther air handling system thus avoiding individual design requirementsfor greenhouse structures as used in conventional practice. The modularsystem therefore allows a purchaser to select a greenhouse size and toknow that all of the design work is carried out so that the climatecontrol will match the size of the greenhouse and the size of thebenches all of which are symmetrical and operate to provide the bestclimate control which is uniform at the plant height.

The length of the benches, in the embodiment shown, is of the order ofeighteen feet so that a construction of four spans of the curtain wallalong the side walls provides an alley at the end of the benches whichis of the order of four feet. However these lengths are merely examplesand can be greater or less as required.

The air handling system of the bench includes the plenum 58, the fan 60and the duct 52. The plenum 50 comprises a rectangular housing standingon the concrete floor 11 and defining a top surface 69 on which thebench tray 55 sits. The bench tray is mounted for pivotal movement abouta hinge 70 at one corner of the housing forming the plenum as best shownin FIG. 3. The bench tray includes a support member 71 which ispivotally connected at the hinge 70 and can fold downwardly to a closedposition sitting on the top surface 69. In the position shown in FIG. 3,the support member 71 is pivoted in a clockwise direction by manuallifting of the bench tray 55 while controlled and assisted by an aircylinder 72. Others of the benches may pivot in the same or oppositedirections as required. The slide bearings 68 are connected between thetray 55 itself and a support member 71 so that the tray slides back andforth on the bearings relative to the support member, when the supportmember is in the lowered position. An interlock (not shown) is providedto prevent sliding movement when the support member is unlocked forlifting so as to prevent uncontrolled sliding movement when the tray ismoved to the open position shown in FIG. 3.

In the open position access to the open top surface 69 is provided whichallows the user to reach into a closing door 73 which acts as a seal forthe top of the plenum to prevent air entry into the plenum except at thedesired inlet locations described hereinafter. When the bench tray ispivoted to the inclined open position shown in FIG. 3, therefore, thedoors 73 can be accessed for opening to allow service work and cleaningwithin the plenum. The air plenum into which air enters is thereforedefined by the door 73 and the sides of the rectangular housing definingthe plenum.

The end wall 58 of the plenum includes an inlet 74 which is covered by agrill to allow the entry of air into the plenum at the end wall formovement along the plenum to the fan 60 under suction generated by thefan. The side walls 75 and 76 of the plenum each have an air inlet 77which is located at the floor 11 and extending along the side of theplenum. The air intake 77 are relatively low forming less than one halfof the height of the plenum so as to take air primarily from the floorlevel.

Inside each of the inlets 74 and 77 is provided a cooling coil 78 and 79respectively. The cooling coil is thus located across the plenum so thatair drawn into the respective inlet passes through the cooling coil.When supplied with cooling fluid, the cooling coil acts to reduce thetemperature of the air drawn into the plenum. Downstream of the threeinlets 74 and 77 is provided a heating coil 80 which is located betweenthe inlets 77 and the fan 60. When supplied with heating fluid, theheating coil will act to apply heat to the air drawn into the fan. Thusby selecting the requisite level of heating and cooling fluid, thetemperature of the air at the fan can be selected in accordance withrequirements so that the air supplied to the plants on the bench traysis at the required temperature.

The fan 60 is mounted in the fan housing which is arranged to butt theend wall 59 of the plenum. The fan is of the centrifugal type defining acircular air inlet 81 and an annular air outlet 82 which ejects the airinto the rectangular fan housing surrounding the annular outlet 82. Aspreviously described the fan housing 51 communicates with an outlet 47in the panel 43. The fan housing 51 has a rear wall 83 at the panel 43which has an opening 84 controlled by flaps 85 which can be moved from aclosed position preventing the escape of air from the fan housingthrough the opening 47 to a controlled open position which allows acontrolled amount of air to escape from the fan housing to the exteriorthrough the opening 47. The opening 84 thus acts as an air outlet forexpelling air from the interior of the greenhouse pulled into the plenumthrough the inlets to the plenum. Makeup air into the greenhouse can bedrawn through roof vents 86 shown in FIG. 5. These roof vents comprisepanels along the roof ridge 26 which are hinged at the roof ridge andcan be pivoted upwardly away from the roof line to provide an opening onthe underside of the roof vent. The climate control system can thereforebe controlled to manage the temperature within the greenhouse by drawingair along the paths marked by the arrows A so that exterior air is drawninto the roof space an expelled through the vent 47.

A duct 87 is also provided through the fan housing from the exteriorinto the plenum 55. The duct 87 is located at a position spaced from theopening 47 and provides an inlet duct connecting with the exteriorthrough the panel 43 and connected onto the suction side of the fan inthe plenum 55. The duct 87 can be controlled by a flap valve 88 so as toallow air from the exterior into the plenum drawn by the reducedpressure of the suction side of the fan. The flap valve 88 is usedseparately from the flap valves 85 so that in a different mode ofoperation air is drawn into the greenhouse through the duct 87 toincrease the pressure inside the greenhouse thus requiring excess air tobe expelled through the roof vent 86.

These different modes of operation of the natural air ventilation systemusing exterior air can be used in different circumstances depending uponthe temperature of the exterior air and the temperature within thegreenhouse. The user can operate the system to provide optimum controlof temperature for maximum consistency by selecting the mode, selectingthe heating, cooling and humidification systems which are optimum in thecircumstances as will be well known to one skilled in this art and toprovide a required amount of fresh air from the exterior.

The vertical duct section 53 is connected to the top wall 61 of the fanhousing so as to receive pressurized air therefrom. The vertical duct 53is arranged at the end wall 14 between the posts 21, 22 close to thepanels. The vertical duct portion is formed from two parallel wallsdefining a front and rear wall which extend from the top surface 61upwardly to a position closely adjacent the roof beams 28 as shown inFIG. 5. The vertical duct thus has a rectangular open bottom mouthdefined by sidewalls 89 and 90 connecting the front wall 91 to the rearwall 92. The side walls 89 and 90 from their position connected with thetop surface 61 of the fan housing converge inwardly to a neck section 93and then diverge outwardly to an upper elbow 94. The elbow 94 has ahorizontal bottom mouth 95 which is rectangular and connects to the topof the vertical duct portion. The elbow 94 forms a vertical mouth 96 atits upper end facing along the greenhouse from the end wall 14 towardthe opposite end wall 15 along the beams 28.

The elbow 94 and the vertical duct section 52 are formed from rigidtransparent plastics material so as to be self supporting and fixedstanding upwardly from the upper surface of the fan housing. These aretransparent material allows the passage of light so as to reduce theinterference with the natural light through the walls of the greenhouse.

The horizontal duct portion 54 is formed from a tubular body of flexibleplastics material which is again transparent or translucent. The tubularbody has a closed outer end 97 spaced outwardly from the open mouth 96of the elbow 94. The opposite open end of the tubular body forming theduct portion 54 is engaged onto the end face 96 of the elbow 94 byhorizontal top and bottom clamping bars 98 and semi-circular end pieces.Thus the flexible tubular body forming the duct portion 54 is heldsubstantially elongate at its open mouth. The tubular body is suspendedfrom the roof beams 28 on straps 99 so as to simply to extend along theroof beams 28 directly over the bench. The tubular body is inflated bythe air from the vertical duct portion but is prevented from forming acircular cylindrical cross section by a plurality of vertical webs 100which are arranged along the length of a tubular body at positionsspaced across the width of the body and standing in a vertical plane.Thus the body when inflated forms generally an elliptical cross sectionwith a wider bottom surface 101 than the height between the top andbottom surfaces which are defined by the webs 100. The bottom surfacehas an array of holes 102 which causes the air to escape from theunderside of the tubular body and flow from the tubular body down towardthe growing plants. The air flow is selected relative to the total areasof holes so that the air escapes from the tubular body under sufficientpressure to generate a velocity at the plants of the order of 50 ft/minwhich is known in the art to provide suitable gas exchange at the plantsurfaces

In the fan housing is also provided a water droplet injection nozzle orfogging system schematically indicated at 103 which includes a controlvalve 104 for controlling the injection of water droplets into the valvehousing from a water supply through a chase 105 located in the chamberunderneath the sill 42. The control system is shown schematically inFIG. 2 and comprises a controlled unit 106 which is arranged to controlthe supply of cooling fluid via cool control 107, to control the supplyof heating fluid through a heating control 108, to control the positionof the vents at the roof and in the fan housing through a vent motorcontrol 109 and to control the supply of water droplets through a valvecontrol 110. The control unit receives inputs from one or more sensors111 which detect the temperature and humidity of the air at the plants.

The humidity of the air can also be carefully controlled either byde-humidifying the air or by adding water droplets at the nozzles 103.Dehumidifying the air is effected by sub-cooling the cooling coils 78 sothat the cooling coil 78 is cooled to a lower temperature than thecooling coils 79. This acts to sub cool the air passing through thecooling coil 78 which extracts moisture from the air which is thensuitably collected at the cooling coil and run to drain. Thus thecooling effect of the cooling coil 79 is relatively reduced in order toprovide a reduction in temperature and the cooling coil 78 of the airwhich is lower than the resultant air temperature required thus actingto extract more moisture at the cooling coil 78 than would be obtainedif all three cooling coils were run at the same cooling temperature. Inextreme conditions of high humidity requiring a reduction in humidityfor the interior of the greenhouse, it may be necessary to run thecooling coil 78 and at the same time to run the heating coil to reheatthe air to the required temperature prior to pumping by the fan back tothe horizontal discharge duct 54.

Humidification of the air is effected simply by the spraying of waterdroplets in a fogging system from the nozzle 103 within the fan housing.Water is supplied to the nozzles at a pressure of the order of 1000 PSIso as to form small droplets from the fogging system which are carriedfrom the fan housing to the duct while evaporating in the air beingtransported through the duct for discharge into the greenhouse above theplants.

The use of the individual duct for each bench ensures that each bench issupplied with the same air in the same quantity and pattern since eachof the air handling systems is managed symmetrically. The use ofrelatively flat wide discharge duct above the bench ensures that the airis deposited with little or no pressure downwardly over the full area ofthe bench so that each location on the bench receives substantially thesame air movement from the duct. The duct is slightly narrower than thewidth of the bench but the location of holes around the hole whole ofthe underside of the duct 54 allows air to be expelled both directlydownwardly and slightly to the sides of the duct.

The lighting system including the rows 23 of lighting elements comprisesa plurality of individual light fixtures 112 mounted on a rail 113.These lighting fixtures includes a reflector and bulb but the ballastunit for the individual lighting fixtures are collected together in acabinet 114 and 115. The control unit and the electrical connections andcontrol elements necessary therefore are provided in plurality ofcabinets 116, 117 and 118. These cabinets are conveniently located asshown in FIG. 8 in the alley 17.

As previously described the structure of the greenhouse is formed bypanels which are inserted between posts where the panels are carried inthe channels defined between the tube member and the cap. The cabinetsare thus conveniently formed as panels which are arranged to be insertedin the alleyway between posts 120, 121 and 122 respectively. Thus thecabinet 114 and the cabinet 117 together form a panel with seals at thetop and sides which allow the panels to co-operate with the channels ofthe posts 120 and 121 and the mullion piece 124 at the top of thepanels. The bottom of the cabinets is raised from the floor and sits ona stand 123 at the bottom with a rear panel of the stand closing thearea underneath the cabinet against communication if air between thealley and the greenhouse.

In a similar manner the cabinets 118 and 115 are mounted in a panel 125which is located between the posts 121 and 122. Again the panels includetop and side seals which engage the posts and mullion bar. The ballastcabinets 114 and 115 generate significant heat so they include inletvents 126 for allowing fan generated air flow cooling.

Thus the pre-formed system of the greenhouse is maintained in thatmodular panels can be supplied for mounting in the location between theposts in the conventional manner previously described so that it is nolonger necessary to manufacture or supply separate electrical cabinetsand the location of those cabinets is conveniently provided for in thealley within the panels. Similarly the cabinet 116 is mounted in thepanel 127 in the wall 16. Because the cabinet 116 is located in theexterior wall 16, it is mounted wholly within the structure so that thepanel runs along the back of the cabinet 116. The cabinets 114. 117, 118and 115 may be mounted as shown so that they project through therespective panel so as a portion of the cabinet is on each side of thepanel. Each of the cabinets has a door or doors which is accessible fromthe alley 17.

The electrical cabinets contain the electrical components provided inthe control system and all other electrical elements including a mainpower supply and a backup power supply in the event of an initial powerfailure.

In a similar manner, each of the doors 18 and 19 is formed as a panel126, 127 so that it can be readily installed as part of the curtain wallsystem by mounting on the posts of the curtain wall system in the walls16 and 15 respectively. Thus the panels 126 and 127 include side panelportions 128 and a top panel portion 129 which surround the door andform the panel into a predetermined dimension matching the width betweenthe posts and matching a required spaced between the floor and a mullionbar. The remaining spaces between the posts can be formed by transparentpanels 31 as previously described or by insulated non transparent fillerpanels 130.

In FIG. 8 is shown one possible location of the water pump system 131for supplying water under pressure of the order of 1000 PSI forsupplying the water nozzles for the humidification system. Additionalwater nozzles (not shown) can also be provided in the area underneaththe horizontal discharge ducts 54 for increased humidification levelsand/or in the area of the roof vents so as to provide water evaporativecooling of the air. The control system 110 previously described controlsthe supply of water from the pump system 131 to the individual nozzlesso as to provide the required effect either within the fan housing orwithin the other areas of the greenhouse as is required and is known topersons skilled in the art.

Turning now to FIG. 10, the pump system 131 is shown in more detailwhich comprises a pump 132 and an accumulator 133. The accumulator 133includes a bladder 134 with nitrogen contained within the bladderinjected from a pressure nozzle 135. The accumulator tank 133 isdesigned to receive and contain the water under the high pressure of theorder of 1000 PSI for supplying the injection nozzles. The outlet to thenozzles is indicated at 136. Water supplied to the pump 132 at an inletline 140 is controlled by a valve 141 and a pressure sensor 142 and ispumped to the pressure of the order of 1000 PSI which is pumped into theaccumulator through a line 143 controlled by valves 137 until thepressure within the accumulator as detected by a pressure valve 138reaches the required maximum operating pressure at which time the pumpis shut off. Water under pressure is then supplied from the accumulatorunder the control of the valve arrangements 139 to the nozzles asrequired. The outlet pressure is maintained above a predeterminedminimum as detected by a pressure detector 138 and when the minimum isreached the pump is reactivated to pump more water into the accumulator.An over pressure valve 145 can detect running of the pump beyond arequired pressure and switches the output of the pump to a drain line146.

In FIG. 11 is shown an alternative arrangement which uses many of thecomponents of the previously described arrangement but is modified toprovide a simplified and therefore less expensive construction which canbe used where a reduced cost is required. In this arrangement, thedirection of operation of the fan 60 is reversed so that it acts to drawair in through the opening 84 so that the opening 84 becomes the airinlet into the plenum. Also in this arrangement, the vertical duct andthe horizontal outlets is removed so that the air driven into the plenumand exits through the openings 74 and 77 so that these openings becomeoutlets rather than inlets.

In order to provide inexpensive cooling, the refrigerated cooling coilsare omitted and are replaced by evaporative cooling elements 178 and 179of a known construction in which water is fed into a suitable supportelement through which the air passes as it moves toward the outlets 74and 77 to effect evaporation of the water on eth support element tocause both cooling and humidification of the air entering thegreenhouse. The elements are generally planar members with the airpassing through at right angles and the water being trickled through themembers.

As a further modification (not shown) which can provide a reducedproduction cost, the plenum can be provided as a separate element fromthe bench so that the bench is supported on simple legs and the plenummerely a rectangular duct without and structural requirements.

Since various modifications can be made in my invention as herein abovedescribed, and many apparently widely different embodiments of same madewithin the spirit and scope of the claims without departing from suchspirit and scope, it is intended that all matter contained in theaccompanying specification shall be interpreted as illustrative only andnot in a limiting sense.

1. A greenhouse comprising: an exterior wall structure which includesprimarily transparent panels allowing entry to an interior of naturallight; a plurality of elongate benches located within the interior andarranged to provide support surfaces for supporting crop materialsthereon for receiving the natural light and growing within the interior;an air handling system for conditioning the air within the interiorincluding at least one air moving fan, at least one interior air intake,at least one interior air outlet, at least one exterior vent and atleast one component for changing air temperature; the exterior wallstructure including a first side and a second side wall opposite to thefirst side wall with each of the first and second side walls defined bya plurality of vertical posts at spaced positions along the length ofthe side wall defining equal spans between each of the plurality ofvertical posts and the next with transparent panels arranged tosubstantially fill the span between the posts; each bench having a benchsupport for the bench located underneath the bench; the benches beingarranged at spaced positions along the first side wall such that eachbench has one end adjacent said first side wall such that the bench andthe bench support therefor each extend from the first side wall at rightangles thereto toward the second side wall; each bench being associatedwith a respective one of the spans such that the number of spans isequal to the number of benches and such that the bench support of eachbench is located between the posts of the associated respective one ofthe spans.
 2. The greenhouse according to claim 1 wherein the width ofeach bench of the plurality of benches is substantially equal to thewidth of the spans.
 3. The greenhouse according to claim 1 wherein theside walls at right angles to said one side wall each have the samespans between the posts thereof and the length of each bench from saidone side wall is equal to a multiple of the spans.
 4. The greenhouseaccording to claim 1 wherein each of the benches is located such that ithas one end at said one side wall and has an opposed end spaced fromsaid opposite wall.
 5. The greenhouse according to claim 1 wherein thespan equals six feet.
 6. The greenhouse according to claim 1 wherein theposts and panels form a curtain wall construction in which the panelsare attached at their edges to the posts and fully extend across thespan therebetween without intermediate support elements.
 7. A greenhousecomprising: an exterior wall structure which includes primarilytransparent panels allowing entry to an interior of natural light; aplurality of elongate benches located within the interior and arrangedto provide support surfaces for supporting crop materials thereon forreceiving the natural light and growing within the interior; an airhandling system for conditioning the air within the interior includingat least one air moving fan, at least one interior air intake, at leastone interior air outlet, at least one exterior vent and at least onecomponent for changing air temperature; the exterior wall structureincluding a first side and a second side wall opposite to the first sidewall with each of the first and second side walls defined by a pluralityof vertical posts at spaced positions along the length of the side walldefining equal spans between each of the plurality of vertical posts andthe next with transparent panels arranged to substantially fill the spanbetween the posts; the benches being arranged at spaced positions alongthe first side wall such that each bench has one end adjacent said firstside wall and extends therefrom at right angles thereto toward thesecond side wall; each bench being associated with a respective one ofthe spans between the posts of said first side wall and arranged suchthat the number of spans is equal to the number of benches; wherein thewidth of each bench is substantially equal to the width of the spans;and wherein at least some of the benches are mounted for side to sidesliding movement and at least one of the benches has a width which isnarrower than that of the spans so as to allow a space between thebenches for user access.
 8. The greenhouse according to claim 1 whereinthe side walls at right angles to said one side wall each have the samespans between the posts thereof and the length of each bench from saidone side wall is equal to a multiple of the spans.
 9. The greenhouseaccording to claim 1 wherein each of the benches is located such that ithas one end at said one side wall and has an opposed end spaced fromsaid opposite wall.
 10. The greenhouse according to claim 1 wherein thespan equals six feet.
 11. The greenhouse according to claim 1 whereinthe posts and panels form a curtain wall construction in which thepanels are attached at their edges to the posts and fully extend acrossthe span therebetween without intermediate support elements.
 12. Agreenhouse comprising: an exterior wall structure which includesprimarily transparent panels allowing entry to an interior of naturallight; a bench arranged to be located within the interior and providesupport surfaces for supporting crop materials thereon for receiving thenatural light and growing within the interior; and and an air handlingsystem comprising: an air intake plenum having at least one air intake,a fan connected to the plenum, an outlet duct connected to the fanhaving an air outlet for expelling air from the duct into the interiorof the greenhouse, and at least one air conditioning component forconditioning the air transported from the plenum to the duct by the fan;wherein the plenum includes at least two inlets and wherein there isprovided at each of the inlets within the duct a cooling coil forcooling the air; and wherein the supply of cooling fluid to each of thecoils is controlled by a cooling system which is arranged to effectsub-cooling at one of the coils for de-humidifying the air.
 13. Agreenhouse comprising: an exterior wall structure which includesprimarily transparent panels allowing entry to an interior of naturallight; a bench arranged to be located within the interior and providesupport surfaces for supporting crop materials thereon for receiving thenatural light and growing within the interior; and and an air handlingsystem comprising: an air intake plenum having at least one air intake,a fan connected to the plenum, an outlet duct connected to the fanhaving an air outlet for expelling air from the duct into the interiorof the greenhouse, and at least one air conditioning component forconditioning the air transported from the plenum to the duct by the fan;wherein the plenum contains fogging nozzles for applying water dropletsto the air; and wherein the fogging nozzles are supplied with waterunder pressure from a fogging water supply system including a water pumpoperable to supply water under pressure to an accumulator tank having agas membrane, the tank being arranged to supply the water under pressureto the nozzles and including a pressure control valve arranged tooperate the pump to maintain the pressure within the tank between upperand lower pressure limits so as operate the pump only when the lowerpressure limit is reached.
 14. A greenhouse comprising: an exterior wallstructure which includes primarily transparent panels allowing entry toan interior of natural light; a bench arranged to be located within theinterior and provide support surfaces for supporting crop materialsthereon for receiving the natural light and growing within the interior;and and an air handling system comprising: an air intake plenum havingat least one air intake, a fan connected to the plenum, an outlet ductconnected to the fan having an air outlet for expelling air from theduct into the interior of the greenhouse, and at least one airconditioning component for conditioning the air transported from theplenum to the duct by the fan; wherein the fan is mounted in a fanhousing with the fan housing at one end of the bench arranged to belocated at one exterior wall of the greenhouse and wherein the fanhousing has a connection for exterior air arranged to extend throughsaid one exterior wall.
 15. A greenhouse comprising: an exterior wallstructure which includes primarily transparent panels allowing entry toan interior of natural light; a bench arranged to be located within theinterior and provide support surfaces for supporting crop materialsthereon for receiving the natural light and growing within the interior;and and an air handling system comprising: an air intake plenum havingat least a part thereof located underneath the bench; at least one airoutlet for expelling air into the interior of the greenhouse; a fanconnected to the plenum for driving air in the plenum from the inlet tothe outlet; and at least one air conditioning component in the part ofthe plenum underneath the bench for conditioning the air; wherein thefan is mounted in a fan housing with the fan housing at one end of thebench arranged to be located at one exterior wall of the greenhouse andwherein the air inlet is arranged to extend through said one exteriorwall.
 16. The greenhouse according to claim 15 wherein the airconditioning component comprises an air cooling device.
 17. Thegreenhouse according to claim 15 wherein the air conditioning componentcomprises a plurality of air cooling devices located at spaced positionswithin the part of the plenum underneath the bench.
 18. The greenhouseaccording to claim 15 wherein the at least one air outlet comprises aplurality of outlets at spaced positions on the part of the plenum underthe bench.
 19. The greenhouse according to claim 18 wherein the at leastone air conditioning component comprises a plurality of evaporative aircooling devices each located at a respective one of the outlets.